import java.util.Scanner;

public class Work1.4 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入您需要的钢管长度（米）: ");
        // 读取用户输入的长度
        double requiredLength = scanner.nextDouble();
        // 计算需要购买的钢管数量
        int numberOfPipes = (int) Math.ceil(requiredLength / 3.0);
        // 输出结果
        System.out.println("您需要购买 " + numberOfPipes + " 根钢管。");
        scanner.close();
    }
}
